At the time of writing, more than 5900 exoplanets have been identified, and thousands more await
confirmation. It is now believed that, on average, every star in our Galaxy hosts at least one planet
in orbit around it. A non-negligible fraction of these trillion worlds may be Earth-like. Among the
main goals of exoplanet research are identifying the key formation and evolution processes that
shape the observed demographics (e.g., radius and mass distributions), understanding the range
of suitable conditions for life, and, ultimately, pinpointing reliable observational biosignatures for
current and next generation IR/optical facilities. In this context, high-energy radiation from the host
star and, less frequently, from galactic transient events plays a crucial role, resulting important in
assessing the likelihood of planetary atmospheric retention and, therefore, in identifying targets that
are suitable for life. This study resumes some results obtained about the process of hydrodynamic
atmospheric escape and the twofold (constructive and destructive) effects of high-energy radiation
on the emergence and maintenance of life.